2000/05/19 by W. Wild, A. Eckart, Wild, W. +1
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0005401
7 pages, 5 figures, accepted by A.&A. 04. May 2000
arxiv created 2000/05/19 · arxiv updated 2009/12/01
The interstellar medium of Centaurus A (NGC 5128) has been studied extensively in recent years, using mostly molecular lines tracing low to medium density gas (500 to several 103 cm-3). The amount and distribution of the dense molecular gas was largely unknown. Here we present new millimeter data of the HCN(1-0), CS(2-1), and CS(3-2) rotational transitions towards the nearby radio galaxy Centaurus A observed with the SEST on La Silla, Chile. We obtained spectra of the HCN(1-0) emission which traces dense 104 cm-3 molecular gas at the center and along the prominent dust lane at offset positions ±60′ ′ and ±100′ ′. We also obtained a few spectra of CS(2-1) and (3-2) tracing densities of ∼105 cm-3. The emission in these lines is weak and reaches a few mK at the available angular resolutions of 54′ ′ - 36′ ′. At the central position, the integrated intensity ratio I(HCN)/I(CO) peaks at 0.064, and decreases to ∼0.02 to 0.04 in the dust lane.